Human kallikrein-2 gene polymorphism is associated with the occurrence of prostate cancer

Human glandular kallikrein, which is encoded by the human kallikrein-2 (KLK2) gene, is significantly associated with the occurrence of prostate cancer (PCa). We tested the association between a functional C748T polymorphism of the KLK2 gene and the occurrence of PCa.

Peripheral venous blood samples were obtained from 254 patients with PCa and 168 controls with benign prostatic hyperplasia. All control subjects had normal serum prostate specific antigen and proved to be free from malignancy on pathological examination of resected prostatic tissues. Serum prostate specific antigen, testosterone, Gleason score, clinical and pathological stage, tumor and prostate volume of the patients were investigated. The KLK2 gene polymorphism was determined by the polymerase chain reaction based restriction fragment length polymorphism method.

The PCa group had a younger mean age +/- SEM (73.0 +/- 0.5 vs 74.7 +/- 0.5 years, p = 0.010) and higher C allele frequency (82.1% vs 74.7%, p = 0.010) than the control group. The frequency of the CC, CT and TT genotypes was 65.7%, 32.7% and 1.6% in patients with PCa, and 56.0%, 37.5% and 6.5%, respectively, in controls (p = 0.010). C allele carriers (CC and CT genotypes) were at significantly higher risk for PCa than TT homozygous subjects (p = 0.002). CC homozygous subjects were at significantly higher risk for PCa than T allele carriers (CT and TT genotypes) (p = 0.043). The PCa subgroup of patients with pathologically proved, localized PCa also had a higher frequency of the C allele (87.5% vs 74.7%, p = 0.026) and CC genotypes (78.7% vs 56.0%, p = 0.019) than controls.

Our results suggest that the C allele of the functional C748T polymorphism of KLK2 may increase the risk of PCa.